Seed-Spacing and Seeding-Depth

S.Seifullin Kazakh Agro-Technical University

Technical faculty

Department of Agricultural and post-harvesting Machines

LABORATORY WORK

) on subject) on subject on subject «Adjustment and linkage of Agricultural machines»

Theme: Drills

Astana 2012

Considered and approved at the meeting of Methodological Council of S.Seifullin Kazakh Agro-Technical University Protocol №___ «___»_______________2012

«APPROVED» Chairman of Methodological Council of S.Seifullin Kazakh Agro-Technical University Protocol №___ _____________A.M.Abdyrov «___»_______________2012

Authors: Yeskhozhin К. – Candidat of Techical Sciense, Associate Professor of the Department of Agricultural and post-harvesting Machines.

Educational-methodical __________ is designed for training on discipline "Fundamentals of tractors" for students on specialty 5B080600 - "Agricultural techniques and technology"

Educational-methodical instructions are made according to the working curriculum of specialty.

Methodical instructions are intended for students of specialties 5В080600 – «Agricultural techniques and technology» and includes laboratory occupation tasks and independent work, educational literature lists and control questions for self-examination.

Reviewers: Doctor of Technical Science, Professor S.O. Nukeshev;

Reviewed and recommended at a meeting of the Department of Agricultural and post-harvesting Machines.

Protocol № ___, of "__" ___________ 2012.

Reviewed and recommended at a meeting of the methodical commission of Technical Faculty.

Protocol № ___, of "__" ___________ 2012.

Purpose of the work:

1. To study the construction of grain drill and its important functions.

2. To study the construction of plough components and its functions.

3. To study the body types of ploughs.

4. Controls and adjustments

5. Ploughing systems

6. Subsoilers

Drills (seeders) and planters are essential for the reproduction of crops. Their function is me­tering and placing in the soil of seeds or plants or of parts thereof. Thus, seeders are used for generative reproduction, where as planters aid in vegetative propagation. However, in some parts of the world, the term planter is used for a seeder. Both seeders and planters are either used as solo machines or in combinations with preceding soil cultivating machines. In some cases, combinations with fertilizing equipment also are common.

Grain drills

Generally, drills (seeders) comprise one or several hoppers, which contain the seeds of me­tering parts, and of equipment for seed placement in the soil. The metering either aims at equidistant spacing of the seeds or is restricted to feeding a stream of seeds into a conveying tube. The former case can be defined as precision seeding, where as for the latter case, the term bulk seeding might be appropriate. Since in most cases the seeds are placed in a row, the definitions of precision drilling as well as bulk drilling make sense.

Figure 1. Conditions for seeding methods.

Precision drilling is used mainly for rather widely spaced crops, such as corn, beans, sugar beets and sunflower. With closely spaced crops, precision drilling is too expensive and therefore bulk drilling common (Fig. 1.).

There are two types of grain drill. One has a mechanical feed mechanism which supplies grain at a controlled rate to the drill coulters, while pneumatic or air drills have a mechanical seed metering unit with an airflow system which distributes the grain through seed tubes to the coulters. Working widths vary from 2.5-9 m and the wider models are folded hydraulically for transport.

Mechanical force feed grain drills may be mounted on the three-point linkage, with small pneumatic tyred drive wheels, or trailed, usually with large diameter wheels. Feed mechanisms in the bottom of the hopper or seed box supply grain in a controlled way to the seed tubes. These direct the seed to the coulters, which make a shallow furrow in the soil. The flexible seed tubes are made from plastic but some older drills with mechanical feed mechanisms have rubber seed tubes. Most drills have a row of closely spaced spring tines on a bar across the full width of the drill to cover the grain.

Figure 2. A 4 m mounted power harrow and drill combination. The markers leave a shallow furrow to help make an accurate join between each bout.

Figure 3. A 24-row studded roller feed grain drill mounted on a power harrow.

Although the coulters on trailed drills are usually raised and lowered into and out of work hydraulically, a mechanical lift clutch does this work on some older drills. The action of raising and lowering the coulters also controls the drive to the force feed seed mechanisms. Seed flow on fully mounted drills is disengaged when the coulters and driving wheels are raised from the ground.

Figure 4. Seedbed preparation and drilling are completed in one operation with this combination cultivator and air-feed drill. Tines at the rear cover the seed.

Seed-Spacing and Seeding-Depth

The mean area per seed with drilled crops is the product of row-spacing and the average seed distance within the row.

Row-spacing varies widely with crops, climatic conditions and production technology. Precision-drilling of crops occurs mainly with row-spacings between 25 cm and 90 cm. Within this span narrow row spacings are used for peas and beans, medium row spacings for beets and sunflower, and the widest spacings for corn. Since in humid areas the water supply allows generally for higher seed and crop densities, row spacing in these areas is closer than in dry regions. Furthermore, mechanical weed control and harvesting methods often require minimum row spacings.

Seed spacing within the row always is a fraction of row spacing, though under ceteris paribus conditions, equal spacings within and between the rows would promote high yields. However, realizing a given seed area by narrower row spacings associated with wider seed distances in the row increases the investment for precision seeding as well as for row-crop harvesting. This is because the number of seeding and row-crop harvesting units increases for a given working width.

With bulk drilling, the row spacing varies between 8 cm and 25 cm. Narrow row spacings are common especially with grass, clover, alfalfa, and small grain seeds in humid areas. Here again average seed spacing within the row always is a fraction of row spacing.

Seeding depth needed depends very much on seed size and on water content of the soil. The larger the seeds and the dryer the soil, the deeper the seeds should be placed to ensure emergence, and vice versa. In most cases, grass, clover, and alfalfa seeds need a soil cover of 1–2 cm; sugarbeet seeds 2–3 cm; small grains, rape, peas, and sunflower between 2–5 cm; and beans and corn between 4 cm and 10 cm.

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